Covering for rolls of textile machines

ABSTRACT

A roll cylinder having a smooth surface and a full-length axle and being free of surface indentations covered with a roll covering comprising a tubular core, a layer of elastomeric material externally mounted on said core and at least one elastomeric rib element internally connected to said core facing and abutting the smooth unindented surface of said roll cylinder; a roll covering adapted to engage the smooth unindented surface of a roll cylinder having a full length axis comprising a tubular core, a layer of elastomeric material externally mounted on said core and a plurality of elastomeric rib elements internally connected to said core and adapted to abut and engage a smooth surface full length roll cylinder on the surface thereof.

States at ent 1191 ayer 1451 Aug. 6, 1974 COVERING FOR ROLLS 0F TEXTILE 2,066,755 1/1937 Wilkie 29/129 MACHINES 2,715,879 8/1955 Sawyer 29/129 X 75 lnventor: Fritz Mayer, Weinheim, FOREIGN PATENTS 0R APPLICATIONS Bergstrasse, Germany 76,212 7/1894 Germany 29/130 [73] Assignee Carl Freudenberg 235,234 4/1926 Great Britain 29/130 weinheim/BergStraSSe Germany Primary Examiner-Alfred R. Guest [22] Fil d; J 4, 1973 Attorney, Agent, or Firm-Burgess, Dinklage &

S 21 Appl. 190.; 366,951 prung I Related US. Application Data ABSTRACT [63] Continuation-impart of Ser. No. 191,467, Oct. 21, A You cylinderhaving a Smooth surface and a full- 1971, abandoned. length axle and being free of surface indentations covered with a roll covering comprising a tubular core, a [30] Foreign Application Priority Data layer of elastomeric material externally mounted on Oct. 24, 1970 Germany 2052249 Said Core and at least one elastomeric rib element ternally connected to said core facing and abutting the 52 us. Cl. 29/129, 29/130 Smooth unindented Surface of Said r911 cylinder; a r011 511 Int. (:1 B21b 31/08 covering adapted to engage the Smooth unindented 5 Field f Search 9 9 95 130, 121 A surface of a roll cylinder having a full length axis comprising a tubular core, a layer of elastomeric material 5 References Cited externally mounted on said core and a plurality of UNITED STATES PATENTS elastomeric rib elements internally connected to said I 273 909 M O,C 29/130 UX core and adapted to abut and engage a smooth surface onnor 1,4 93 2 5 7 5,1924 Gamer IIIIIIIIII n full length roll cylinder on thesurface thereof. 1,619,371 3/1927 Rogers et al. 29/130 UX 6 Claims, 8 Drawing Figures PATENTED nus 8:974

SHEET 1 0f 3 COVERING FOR ROLLS OF TEXTILE MACHINES CROSS REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of application Ser. No. 191,467, filed Oct. 21, 1971 now abandoned.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention is directed to roll coverings.

More particularly, this invention is directed to roll coverings for large roll cylinders extensively employed in machinery utilized in the textile industry. More especially, this invention is directed to a roll covering which is adapted to engage the smooth, unindented surface of a full length roll covering through the use of at least one internally disposed elastomeric rib element which engages the smooth, unindented surface of the roll cylinder.

2. Discussion of the Prior Art It is known to draw rubber rolls on to a roll cylinder. For this purpose, the inside diameter of the tubular rubber covering is made somewhat smaller than outside diameter of the top roll cylinder. For this purpose, the inside diameter of the tubular rubber covering is made somewhat smaller than the outside diameter of the top roll cylinder. If the diameter of the tubular covering is appreciably smaller than the outside diameter of the cylinder, the covering will, of course, cling more tightly to the cylinder. This assures precise seating of the covering at first, but the greater the tension of the covering is, the shorter its life will be.

Attempts have theretofore been made to diminish this tension, but reductions of tension reduce the security with which the covering is held on the cylinder. Friction may be produced, as well as slippage between the cylinder and the covering.

To prevent this slippage, the surface of the cylinder has been coated with an adhesive. This method of installation, however, requires a careful match between the diameters of the cylinder and of the covering. Also, the life of the applied adhesive is subject to certain limitations. After cementing, the cylinder with its covering has had to be let stand for a relatively long time to enable the bonding agent to cure.

Furthermore, the replacement of such a covering is troublesome. Residues of adhesive and rubber have to be scraped from the top roll cylinder by a tedious process before new adhesive and a new covering can be applied.

It has therefore already been proposed that the rollcovering first be pressed on to a metal cylinder core. Such a covering mounted on a metal core is then slipped over the top roll cylinder. With these metalcore coverings, however, extremely close tolerances have to be observed, thereby raising the cost of such metal-core-stretched coverings.

It has also been proposed to provide roll coverings for full-length axled roll cylinders where the surface of the roll cylinder is provided with an indentation running the length thereof, in which there can be placed in engagement 3 cooperating member on the roll cover ing. Thus, it has been proposed to provide a longitudinal keyway in the roll cylinder itself into which a longitudinal key on the roll covering is inserted. Obviously this requires a machining of the roll cylinder which can impart certain weaknesses to the roll cylinder. Moreover, there is usually required a locking technique where the longitudinal key on the roll covering is locked in engagement within the keyway on the roll cylinder. Quite apparently, such method of construction is expensive and requires close coordination between the dimensions of the keyway in the roll cylinder and the dimensions of the longitudinal key internally mounted in the roll covering. Such construction is shown in US. Pat. No. 1,493,257.

There are other types of roll coverings employed but generally these types are employed in apparatuses, wherein there is only a pair of facing end hubs, i.e., there is no full length axle for the roll cylinder. Such roll coverings generally have a decidedly different construction in that they do not have to abut the roll cylin der over its entire length.

SUMMARY OF THE INVENTION Broadly, this invention contemplates a roll cylinder having a smooth surface and a full length axle and being free of surface indentations covered with a roll covering comprising a tubular core, a layer of elastomeric material externally mounted on said core and at least one elastomeric rib element internally connected to said core facing and abutting the smooth, unindented surface of said roll cylinder. Preferably, the elastomeric rib element abuts the smooth surface of the roll cylinder over a distance of at least fifty percent of the common length of the roll cylinder and roll covering.

As stated above, the roll covering of the present invention is provided with at least one internally connected elastomeric rib element. The purpose of such elastomeric rib element is to run in contact with the smooth surface of the internally disposed roll cylinder over a major amount of the length thereof. Such length refers to the common length that the roll covering and roll cylinder have. Thus, conceivably, a roll covering can cover less than all of the surface of a roll cylinder. The elastomeric rib element engages, obviously, only that portion of the roll cylinder disposed therebeneath. Preferably, the rib element is in contact with the roll covering over at least 50 percent of the common length, more preferably at least percent and most desirably over its entire length.

At the heart of the present invention is a roll covering comprising a tubular core, a layer. of elastomeric material externally mounted on the core and at least one elastomeric rib element internally connected to the core and adaptable to face and abut the smooth, unindented, surface of a roll cyllinder. Preferably such rib element or rib elements traverse at least 50 percent of the length of the roll covering, more preferably 80 percent and most desirably the entire length thereof.

BRIEF DESCRIPTION OF DRAWINGS Referring to the drawings herein:

FIG. 1 is an isometric view of a roll covering for a cylinder pursuant to the invention;

FIG. 2 is a cross-sectional elevation of a section of the roll cover of FIG. I viewed from the side;

FIG. 3 is a sectional view taken along the line A A of the roll cover of FIG. 2;

FIG. 4 is an isometric view similar to FIG. 1, said view partially broken away, showing the disposition of the roll covering about a smooth surface, unindented, interially disposed roll cylinder having a full axis;

FIG. 5 is a sectional view taken along the line 5 5 of FIG. 4;

FIG. 6 is a sectional side elevation of a portion of a mold employed in the formation of a roll cover of FIG.

FIG. 7 is a view similar to FIG. 6 of a facing portion of a mold employed in the formation of the roll cover of FIG. 1;

FIG. 8 is another portion of the mold employed in the formation of the roll cover of FIG. 1 which figure is similar to FIGS. 6 and 7, all as well appear more fully from the disclosure below.

BRIEF DESCRIPTION OF THE INVENTION Referring to the drawings herein:

FIG. 1 shows a plurality of interiorly disposed internally mounted elastomeric rib elements 1, mounted to a core member 2 over which is disposed a layer of elastomeric material externally mounted to such core, said layer of elastomeric material being represented by reference numeral 3. In FIG. 2, it is seen that the elastomeric internally disposed rib elements 1 face one another and the space to be occupied by a full length smooth surface unindented roll cylinder. The relationship of these parts can be further seen in FIG. 3, a sectional view of the apparatus depicted in FIG. 2, such section being taken along the lines A A of FIG. 2. It is apparent that it is preferred that the combined width of the rib element be at least forty percent of the circumference of the roll cylinder on which the roll covering is to be placed. Preferably, there are at least four opposed elastomeric rib elements. From FIG. 3, it can be seen that the rib elements generally traverse the entire length of the roll covering, although, conceptually, it is adequate if they traverse only 50 percent of such length. The core member which carries the elastomeric ribs, i.e., the member to which the elastomeric ribs can be attached can be made of any suitable material, especially metal or plastic.

Referring to FIG. 4, and especially to FIG. 5, there is shown the manner in which a plurality of rib elements engage the surface of the roll cylinder. Through use of the elastomeric nature of such rib elements 1, the entire roll covering assembly can abut the roll cylinder 20. This roll cylinder has a smooth surface 22, i.e., it is free of indentations in the nature of a keyway or other indentations which function to lock with an element on the roll covering. The rib elements sufficiently adhere the entire roll covering assembly to the roll cylinder that the roll cylinder can be rotated at extremely high speeds without damage to the roll covering and without the possibility of slippage of the roll covering with respect to the roll cylinder. For instance, the roll covering can be employed on drafting machines employed in fiber processing wherein exceptionally high speeds are employed. Thus, the roll coverings can be employed in the drafting system of ring spinning machines.

In order to more fully illustrate the nature of the invention and the manner of practicing the same, the following example is presented:

In order to produce a roll covering in accordance with with invention having an outside diameter of 30.6 mm, a length of 26 mm and an inside diameter (measured from one metal surface to the other) of 18.7 mm,

with ribs having a thickness of 0.35 mm, the mold shown below is used, in which all dimensions are given in millimeters.

The mold consists, as shown in FIG. 6, of the bottom part III. The bottom part bears the core K over which there is drawn a metal tube having an inside diameter of 18.7 mm, the solid line representing the metal contact surface with inside of the sleeve (which is not shown). The broken line shows the fluting in the core for producing the rubber ribs on the inside of the metal sleeve.

After the metal sleeve (not shown) has been put in place, the middle part II of the mold (FIG. 8) is placed over the bottom part III, and it contains the procket A into which a rubber blank is inserted. By means of the piston I (FIG. 7) which plunges into the pocket A the rubber compound is forced under heat and pressure (C; 200 atmospheres gauge) into part B of Mold II, filling the gap between the cord K and the central aperture of part II. This takes place through six bores laterally of portion C. A covering approximately 6 mm thick is thus formed on the outside of the sleeve. On the inside of the metal sleeve eight ribs of a thickness of 0.35 mm and a width of 2 mm are formed.

The manufacturing is thus performed by the transfer molding process.

One special advantage of the manufacturing process on which the invention is based is that, due to the pressing or injection of the rubber or elastomer into a mold and the simultaneous vulcanization of the rubber or cross-linking of the elastomer that takes place, there is no tension in the rubber or elastomer, and this results in greatly improved resistance to aging.

From the above description, it is apparent that the roll covering of the present invention is highly useful on existing roll cylinders. It does not require the use of adhesive and accomplishes a highly efficient junction of the roll covering to the roll cylinder. The roll covering can, however, be readily withdrawn from the roll cylinder should it be desired to replace such roll covering with another surface or, should it be desired, to inspect the surface of the roll cylinder. Moreover, the roll covering of the present invention can be prepared from readily available materials. The nature of the elastomeric material comprising the outsurface 3 is not particularly critical and is dictated by the use to which the roll covering will be placed. The rib elements 1 are resilient so that they can be deformed inwardly when the roll covering is slipped over the full length axle of the roll cylinder. Due to its resilient elastomeric nature, the rib elements I bear against the smooth surface 22 of the roll cylinder 20 and exert a pressure of sufficient magnitude to hold the entire roll covering assembly thereto so that the over-all assembly comprising the roll cylinder and roll covering function as an integral unit.

The terms and expressions used herein have been used as terms and expressions of description and not of limitation as there is no intention, in the use of such terms and expressions, of excluding any equivalents, or portions thereof, as various modifications and departures from the above disclosure will be apparent to one skilled in the art.

What is claimed is:

l. A roll cylinder having a smooth surface and a full length axle and being free of surface indentations covered with a roll covering comprising a tubular core, a

4. A roll cylinder according to claim 3, wherein said elastomeric rib element runs the entire length of the internal portion of said roll covering.

5. A roll cylinder according to claim 2, wherein there are a plurality of internally connected elastomeric rib elements.

6. A roll cylinder according to claim 5, wherein the combined width of the rib elements is equal to at least 40 percent of the circumference of the roll cylinder. 

1. A roll cylinder having a smooth surface and a full length axle and being free of surface indentations covered with a roll covering comprising a tubular core, a layer of elastomeric material externally mounted on said core and at least one elastomeric rib element internally connected to said core facing and abutting the smooth unindented surface of said roll cylinder.
 2. A roll cylinder according to claim 1, wherein said elastomeric rib element runs at least 50 percent of the common length of the roll cylinder and the roll covering.
 3. A roll cylinder according to claim 2, wherein said elastomeric rib element runs at least 80 percent of the length of said roll covering.
 4. A roll cylinder according to claim 3, wherein said elastomeric rib element runs the entire length of the internal portion of said roll covering.
 5. A roll cylinder according to claim 2, wherein there are a plurality of internally connected elastomeric rib elements.
 6. A roll cylinder according to claim 5, wherein the combined width of the rib elements is equal to at least 40 percent of the circumference of the roll cylinder. 